Improvement in chucks



J'. H. WESTCOTT.

cHU'cKs.

Patented Feb.13,1877.

rNo.1'87,4`38.

www Iii iii!" HIIHIIII Unrrnnr Partnr Orr-ron Jenni n. .wnsfrcomn vonemilion, NEW Yoan.

Y IMPRcvEMi-:NT jlNcHucK's.

Specification forming partof Letters Patent No. 18:7,438`Q`4datedFebruary 13, 1877-; application tiled e l January 12, 1877, i l j e e vther a universal or independent action may be obtained for themthat is,so that their holding-jaws may either be collectively and simultaneouslyadjusted, or each jaw be separately and independently adjusted, ascircumstances require.

. The invention consists in a novel construcv tion and combination ofparts, including a loose ring inserted within the-shellof the chuckunder cover thereof, and having a series of recesses corresponding withthe screws by which the jaws are adjusted for operation in relation withfixed inclines in the shell under or at the back of the pinions, bywhich the jaws are adjusted to provide for setting a circular rack undercover of the shell in or out of gear with said pinions. Said loose ringhas attached to it a stud, which projects through a slot in the back ofthechuck, which slot is provided with 'enlarged end openings, for a nutscrewing onto said stud to enter within and hold the ringin or out ofgear with the pinionson the jaw-screws.

By this construction and combination ot' parts there is virtually noexposure of the working parts, the circular rack is supported when ingear with the pinions which operate the jaw-adjusting screws immediatelyunder or at the back of said pinions, and the weight and thickness ofthe chuck is reduced, over or as compared with other universal andindependent chucks employing a circular rack put into or out of gear, asrequired, with the pinions which operate the jaws of the chuck.

Figuresland 2 represent interior face views of the two halves of thechuck, in transverse relation with the latter, as detached from eachother. Fig. 3 is a section, mainly on the line i a: a, in a longitudinaldirection with the axis of the chuck; and Figs. 4 and 5, sections uponan enlarged scale, in direction of the line yy, of certain of theworking parts, showing respectively the circular rack in and out of'gear with the pinions by which the jaws are operated.

A is the one half-shell of the chuck, and B the other half thereof,united in the usual or any suitable manner.

C O are the holdingjaws, of which there may be three o r more, and whichare set in or out by means of screws D D, working ,through nuts orsliding boxes E E To effect thehindependent adjustment of the jaws O G,a wrench is applied to the outer ends of either of the screws D D, whennot coupled to work together.

To provide for a simultaneous adjustment of said jaws, .a circular rack,G, is put intoY gear with the pinions H on the screws D D.

The circular rack G is itted to freely turn within the back half-shellB, and is free'to be adjusted in or out in an axial direction, with saidshell within the latter, and under cover Y thereof.

At the back of said circular rack'G, and

ments has been effected, the nut J is screwed down or entered Within one0r other of enlarged recesses c c at the ends of the slot b, to hold thecircular rack G in or out of gear with the pinions H H. To accomplishthis in asiinple, light, efficient, and durable manner, the ring S ismilled at its back, or constructed with a series of recesses,f,corresponding with the number of screws D D, by which the jawsl areadjusted, and the interior surface of the shell portion B, over oragainst which the ring S works, is constructed or provided with a seriesof lixed convex or inclined projections, g,

under or at the back of the pinions H, whereby the pinions are firmlyheld in position.

When the ring S is adjusted by the stud I or nut J in a circulardirection relatively to the axis of the chuck, to bring those portionsof its backwhich are not recessed over the convex or inclinedprojections g, then the eircular rack G is put in gear with the pinionsH of the jaw-adjusting screws D, as shown in Fig. 4, to provide for theuniversal adjustment of the chuck through the circular rack G, by Wrenchapplied to either one of the outer ends of the screws D. When, however,said ring S is adjusted to bring its milled or recessed portions f overor in line with the projections g, then the circular rack Gis free toclear itself` of the pinions H, asshown in Fig. 5; so that the severalscrews -D maybe separately operated to provide for an independentadjustment of the holding-jaws G.

I claim- The shell portion B, 'constructed with a slot, b, in its back,having enlarged endslc c, in combination with the screw-stud I, fast tothe ring S and the nut J, essentially as and for the purpose herein setforth.

JOHN H. WESTGO'IT.

Witnesses: Y

RoBER T' J FISH,

THEODORE F. HAND.

